c++运算符重载
用成员函数重载运算符：
1 #include "stdafx.h" 2 #include<iostream> 3 using namespace std; 4 class Complex { 5 private: 6 double real, imag; 7 public: 8 Complex(double r = 0.0, double i = 0.0); 9 Complex operator+(Complex c); 10 Complex operator-(Complex c); 11 void display(); 12 }; 13 14 Complex::Complex(double r, double i) 15 { 16 real = r; 17 imag = i; 18 } 19 20 Complex Complex::operator+(Complex c) 21 { 22 Complex temp; 23 temp.real = real + c.real; 24 temp.imag = imag + c.imag; 25 return temp; 26 } 27 28 Complex Complex::operator-(Complex c) 29 { 30 Complex temp; 31 temp.real = real - c.real; 32 temp.imag = imag - c.imag; 33 return temp; 34 } 35 36 void Complex::display() 37 { 38 char ch; 39 ch = (imag < 0) ? ' ' : '+'; 40 cout << real << ch << imag << "i" << endl; 41 } 42 43 int main() 44 { 45 Complex c1(12.4, 13.3); 46 Complex c2(14.4, 26.5); 47 Complex c; 48 cout << "c1="; 49 c1.display(); 50 cout << "c2="; 51 c2.display(); 52 c = c1 + c2; 53 cout << "c1+c2="; 54 c.display(); 55 c = c1 - c2; 56 cout << "c1-c2="; 57 c.display(); 58 return 0; 59 }
用友元函数重载运算符：
1 #include "stdafx.h" 2 #include<iostream> 3 using namespace std; 4 class Complex { 5 private: 6 double real, imag; 7 public: 8 Complex(double r = 0.0, double i = 0.0); 9 friend Complex operator+(Complex c1,Complex c2); 10 friend Complex operator-(Complex c1,Complex c2); 11 void display(); 12 }; 13 14 Complex::Complex(double r, double i) 15 { 16 real = r; 17 imag = i; 18 } 19 20 Complex operator+(Complex c1,Complex c2) 21 { 22 Complex temp; 23 temp.real = c1.real + c2.real; 24 temp.imag = c1.imag + c2.imag; 25 return temp; 26 } 27 28 Complex operator-(Complex c1,Complex c2) 29 { 30 Complex temp; 31 temp.real = c1.real - c2.real; 32 temp.imag = c1.imag - c2.imag; 33 return temp; 34 } 35 36 void Complex::display() 37 { 38 char ch; 39 ch = (imag < 0) ? ' ' : '+'; 40 cout << real << ch << imag << "i" << endl; 41 } 42 43 int main() 44 { 45 Complex c1(12.4, 13.3); 46 Complex c2(14.4, 26.5); 47 Complex c; 48 cout << "c1="; 49 c1.display(); 50 cout << "c2="; 51 c2.display(); 52 c = c1 + c2; 53 cout << "c1+c2="; 54 c.display(); 55 c = c1 - c2; 56 cout << "c1-c2="; 57 c.display(); 58 return 0; 59 }
单目运算符重载（自加·自减）
用成员函数重载运算符：
1 #include "stdafx.h" 2 #include<iostream> 3 using namespace std; 4 class Counter { 5 private: 6 unsigned value; //unsigned不加类型名时，默认表示无符号整型 7 public: 8 Counter() { value = 0; } 9 Counter(int i) { value = i; } 10 Counter operator++(); 11 Counter operator++(int); 12 Counter operator--(); 13 Counter operator--(int); 14 void display() { cout << value << endl; } 15 }; 16 17 Counter Counter::operator++() 18 { 19 value++; 20 return *this; 21 } 22 23 Counter Counter::operator++(int) 24 { 25 Counter temp; 26 temp.value = value++; 27 return temp; 28 } 29 30 Counter Counter::operator--() 31 { 32 value--; 33 return *this; 34 } 35 36 Counter Counter::operator--(int) 37 { 38 Counter temp; 39 temp.value = value--; 40 return temp; 41 } 42 43 int main() 44 { 45 Counter n(10); 46 Counter c; 47 c = ++n; 48 cout << "前缀++运算符计算结果:" << endl; 49 cout << "n=", n.display(); 50 cout << "c=", c.display(); 51 c = n++; 52 cout << "后缀++运算符计算结果:" << endl; 53 cout << "n=", n.display(); 54 cout << "c=", c.display(); 55 c = --n; 56 cout << "前缀--运算符计算结果:" << endl; 57 cout << "n=", n.display(); 58 cout << "c=", c.display(); 59 c = n--; 60 cout << "后缀--运算符计算结果:" << endl; 61 cout << "n=", n.display(); 62 cout << "c=", c.display(); 63 return 0; 64 }
用友元函数重载运算符：
1 #include "stdafx.h" 2 #include<iostream> 3 using namespace std; 4 class Counter { 5 private: 6 unsigned value; //unsigned不加类型名时，默认表示无符号整型 7 public: 8 Counter() { value = 0; } 9 Counter(int i) { value = i; } 10 friend Counter operator++(Counter&); 11 friend Counter operator++(Counter& ,int); 12 friend Counter operator--(Counter&); 13 friend Counter operator--(Counter& ,int); 14 void display() { cout << value << endl; } 15 }; 16 17 Counter operator++(Counter& p) 18 { 19 p.value++; 20 return p; 21 } 22 23 Counter operator++(Counter& p,int) 24 { 25 Counter temp; 26 temp.value = p.value++; 27 return temp; 28 } 29 30 Counter operator--(Counter& p) 31 { 32 p.value--; 33 return p; 34 } 35 36 Counter operator--(Counter& p ,int) 37 { 38 Counter temp; 39 temp.value = p.value--; 40 return temp; 41 } 42 43 int main() 44 { 45 Counter n(10); 46 Counter c; 47 c = ++n; 48 cout << "前缀++运算符计算结果:" << endl; 49 cout << "n=", n.display(); 50 cout << "c=", c.display(); //这句话相当于 cout<<"c="; 51 c = n++; //c.display(); 52 cout << "后缀++运算符计算结果:" << endl; 53 cout << "n=", n.display(); 54 cout << "c=", c.display(); 55 c = --n; 56 cout << "前缀--运算符计算结果:" << endl; 57 cout << "n=", n.display(); 58 cout << "c=", c.display(); 59 c = n--; 60 cout << "后缀--运算符计算结果:" << endl; 61 cout << "n=", n.display(); 62 cout << "c=", c.display(); 63 return 0; 64 }
最后来一组运行结果：
